Process of producing rubber articles



Patented Sept. 15, 1936 v 2,054,780

UNITED STATES PATENT orric s raocnss or PRODUCING RUBBER narrows RudolphS. Bley, Elizabethton, Tenn., assignor to North American RayonCorporation, New York, N. Y., a corporation of Delaware No Drawing.Application April 3, 1935,

Serial No. 14,469

1 Claim. (on. sat-st) The present invention relates to a process mainingin the regenerated cellulose, such as of producing reinforced vulcanizedrubber arviscose, tend to oxidize rubber. Since it is a ticles.wellknown fact that rubber is decomposed, or

The principal object of this invention has to aged, rapidly in thepresence of oxidizing agents,

5 do with the incorporation of desulphurized but it isnecessary to addanti-oxidants to rubber 5 unbleached rayon yarns and fabrics into rubbercompositions. For this reason the imbedding of I before thevulcanization thereof. bleached-rayon is detrimental to the keepingOther objects of this invention will become apqualities of vulcanizedrubber products. These parent to thoseskilled in the art from a studydeficiences of either undesulphurized or desulof the followingspecification. phurized, bleached rayon may be overcome by- 10 I am wellaware that it has, heretofore, been using desulphurized but unbleachedviscose silk. proposed to replace cotton fabrics by rayon fab- Any typeof viscose rayon may be used in combirics in vulcanized rubber articles,and that unnation with suitable rubber compositions prodesulphurizedrayon has been used for this purvided it i thoroughly desulphurized andpose. U. S. Patent 1,902,871 to George R. Lock-' bleached. This rayonmay be used either in the i5 hart of March 28, 1933, for example,discloses a form of yarns or fabrics to satisfactorily replacevulcanized rubber article containing undesulcotton heretofore used inthe rubber art. By phurized rayon. Contrary to the allegation thatimbedding the rayon in rubber, it may be imthe sulphur particles presentin undesulphurized pregnated with suitable accelerators, thin rubr y nfilaments and yarns assist vulcanization bet solutions with 'or withoutaddition of .vui- 20 and promote adherence of the rayon to thesurcanizing agents, etc. In addition, to promote rounding rubber mass, Ihave found that the suladherence of the viscose rayon to rubber, it mayphur does not exert this beneficial assistance be roughenedby suitablemeans. -I wish to emon he n r ry, in u es a w k nin f th phasize thatthe use of desulphurized, unbleached 250311111056 when the rubberContaining undesulviscose rayon in vulcanized rubber products is p ur dray n is hea e t vu niz tion t mnot only economical, but that iteliminates the perature. In my opinion, the detrimental effectimpregnation of regenerated cellulose with form- Of Sulphur. present inundesulp ur d ay aldehyde, necessary to counteract the destrucis to beexplaind y the fact that ul tive action of sulphur upon cellulose, asdisclosed forms at vulcanization temperature hydrogen i th at nt toLockhart, set forth above, 0 u phid h Sulphur (Vide P Modifications ofmy invention will be readily hers ,895 and 1,9 y 1935, recognized bythose skilled in the art, and I t d to R S. Bley). e hyd sulphide wishto include all such modifications falling formed does not only fail topromote vulcanizaithi th scope of the appended claim.

tion of the rubber, but it tends to loosen the 1 lai 35 ce u ose O eSurrduhdihg rubber- An article of manufacture consisting of I have,furthermore, found that ordinary vulcanized rubber having imbeddedtherein sulphurized and bleached rayon, heretofore constrengtheningthreads of desuiphurized, unventionally used in combination with rubber,does bl h d rayon,

40 not yield a satisfactory product for the reason RUDOLPH s. BLEY. 40that the small residues of bleaching agents re- I

